(a) Field of the Invention
The invention relates to a turning disc intermittent rotary mechanism, and more particularly, to an innovation from the patent application disclosed by the U.S. application Ser. No. 09/844,900.
(b) Description of the Prior Art
In the patent application of the present inventor disclosed by the U.S. application Ser. No. 09/844,900, the techniques thereof are that a small pulley 34 rotates regarding an axis of a main driving wheel 30 as the center of rotation thereof, so that the small pulley 34 is enabled to move inside plum blossom-patterned sliding slots 14 and further impel the intermittent rotation and dwelling of a top disc 10.
Although the above patent application is indeed quite practical, improvements shall yet be made in the long term as illustrated hereunder.
Referring to FIG. 6 showing a planar view illustrating the bottom surface of the top disc 10 in accordance with the patent application disclosed by the U.S. application Ser. No. 09/844,900, when the small pulley 34 rotates in the plum blossom-patterned slots 14, the small pulley 34 acts and generates a force against the slot walls for further impelling the action region, namely the long sliding slot 143, of the turning disc. The radian of the arcuate sliding slot therein 146 is the same as that of the small pulley 34, and therefore the small pulley 34 does not produce an effective force against the slot wall of the arcuate sliding slot 146. The small pulley 34 then displaces in idle, and the top disc is resultingly in a brake state without any rotation. On the other hand, when the small pulley 34 slides and moves in circulation in the arcuate sliding slot 146 and the long sliding slot 143, the top disc 10 is impelled for intermittent pauses and rotation. When the force of the small pulley 34 acts at the region of the long sliding slot 143, the center of the small pulley 34 forms a short lever of force R1 with the center of a through hole 12; when the small pulley 34 runs idle in the arcuate sliding slot 146, the center of the small pulley 34 forms a long lever of force R2 with the center of the through hole 12. It is apparent that when the small pulley 34 impels and acts at the long sliding slot 143, the force of the small pulley 34 acting against the slot wall of the long sliding slot 143 is correspondingly larger because of the larger force of the small pulley 34 acting at the long sliding slot 143 due to the shorter length of the short lever of force R1. Vice versa, although the long lever of force R2 is longer in length, it does not act against (no force is produced) the slot wall of the arcuate sliding slot 146. For that the length of the short lever of force R1 is shorter and the force (power) of the small pulley 34 for impelling and rotating the top disc 10 is correspondingly larger, the friction between the small pulley 34 and the long sliding slot 143 is consequently increased, exposing the small pulley 34 to larger damages when the transmission mechanism operates in the long run.